In the manufacture of glass fiber strands as practiced today the emphasis is on increased productivity for each fiber forming position located on the forehearths of the furnaces used to process the raw glass making ingredients into molten glass. The glass, once molten, flows from the forehearth of the furnace through the fiber forming bushings which produce multiple streams of glass from a multiplicity of holes of precise dimension. These streams of molten glass solidify as they leave the bushing are gathered together to form strands after usually having a size or binder applied to them and are then collected on a paper or plastic tube which is rotated at high speed on the surface of a winding machine. The paper tube with the collected glass is slipped off of the winder when it is stopped upon completion of a package forming cycle.
The winder used to form the glass fiber packages are used both to wind the glass strands thereon and to impart the attenuation forces to the molten glass streams that are forming glass fibers as they emerge from the bushings. In a modern fiber glass manufacturing facility these winders operate at speeds that result in strands being collected at 12,000 to 20,000 feet per minute (3,658 to 6096 meters per minutes). In addition to operating at high speed, the winders are increasing in size and weight. The net result of the necessity to achieve high rates of production from the winding of the glass is that the costs of the winding equipment now represents a substantial capital investment in an industry that is already burdened with high capital costs for furnaces and the platinum alloys used to fabricate the bushings that produce the fibers.
Typical of the winders that are used to collect glass fiber strands in forming are those shown in U.S. Pat. Nos. 3,151,963, 3,041,663, and 3,547362. These winders are positioned below a forming bushing and after the strands are formed are rotated at high speeds to collect the product. The high collection speeds employed impart considerable tension to the strands that are collected which wrinkles the forming tubes used on the winder to collect the strands. High speeds also cause broken filaments, and more importantly, cause quality defects with inconsistent strands being poduced in the same package.
For these and other reasons a need exists to provide a method of winding strands of glass fibers that is less expensive than the high technology winders now employed but that will duplicate their productivity and minimize their product quality shortcomings. The instant invention satisfactorily meets that need.